The present invention relates generally to intravascular guidewires. More particularly, the present invention relates to steerable guidewires.
Intravascular catheters are currently utilized in a wide variety of minimally-invasive medical procedures. Generally, an intravascular catheter enables a physician to remotely perform a medical procedure by inserting the catheter into the vascular system of the patient at an easily accessible location and urging the catheter forward through the vasculature until the tip of the catheter is proximate a desirable target site. By this method, virtually any target site in the patient""s vascular system may be remotely accessed, including the coronary, cerebral, and peripheral vasculature.
A physician attempting to position a catheter within a patient""s vascular system may encounter a number of challenges. For example, the target site may be located a relatively long distance from the access site. By way of a second example, the path taken by a catheter through the vascular system may be tortuous, requiring the catheter to change direction frequently. In some cases, it may even be necessary for the catheter to double back on itself. A guidewire may be utilized to aid in advancing a catheter through the vasculature of a patient.
A guidewire may be inserted into the vascular system of the patient at an easily accessible location and urged forward through the vasculature until the tip of the guidewire is proximate a desirable target site. A proximal end of the guide wire may then be inserted into a guidewire lumen of a catheter. The tip of the catheter may be advanced along the length of the guidewire until it reaches a desirable target site.
The present invention relates generally to intravascular guidewires. More particularly, the present invention relates to steerable guidewires. A guidewire in accordance with one embodiment of the present invention includes a shaft assembly having a distal end and a proximate end. The shaft assembly includes a coil defining a lumen and a wire disposed in the lumen of coil. A distal end of coil is fixed to a tip member. Likewise, a distal end of the wire is fixed to tip member. The wire extends beyond a proximal end of the coil forming a proximal portion of the wire terminating at a proximal end of the wire.
In a presently preferred embodiment, the wire includes a curved portion disposed proximate the distal end of the shaft assembly. In this presently preferred embodiment, the curved portion of the wire urges the coil into a substantially curved shape. Also, in a presently preferred embodiment, the curved portion of wire is biased to return to a generally curved shape after being deflected.
In a method in accordance with the present invention, a guidewire may be inserted into the vascular system of a patient and urged forward through the vasculature until the tip member of the guidewire is proximate a desirable target site. As the guidewire is advanced through the vasculature of a patent, it may be necessary to xe2x80x9csteerxe2x80x9d the guidewire. For example, the distal end of the guidewire may reach a branch in the vasculature. The physician may direct the distal end of the guidewire toward the desired branch of the vasculature. Curved portion of wire may facilitate the steering process. Torsional forces may be applied to the proximal portion of the guidewire to alter the angular orientation of curved portion relative to the blood vessel. In this manner, the distal end of guidewire may be directed into the ostium of a desired vessel.
A method of steering a guidewire in accordance with the present invention may include the step of altering the curvature of distal portion of the guidewire. The step of altering the curvature of distal portion of the guidewire may be accomplished by urging a proximal portion of the wire proximally with respect to the proximal end of coil. Once the guidewire is positioned, the proximal end of guidewire may be inserted into a guidewire lumen of a catheter. The tip of the catheter may be advanced along the length of the guidewire until it reaches a desirable target site. In this manner, the guidewire aids the physician in delivering the distal tip of the catheter to the desired target site.